Zero insertion force connector

ABSTRACT

A thin, board-to-board zero force insertion and withdrawal connector having a housing containing a plurality of contacts with a first end portion of the contacts secured therein. A pair of parallel rows of rib-like elements extend along the length of the housing and define a U-shaped slot into which the edge of a circuit board can be inserted. The ribs form grooves therebetween which are perpendicular to the rows of ribs. The other end portion of each of said contacts extends downwardly into a groove towards the inner sides of said rib-like elements defining a side of said U-shaped slot, and then further extends upwardly towards the outer side of said rib-like elements. A plate is positioned along the length of said housing and secured thereto by a flexible hinge which divides the plate longitudinally along its length into two sections. A first of these sections extends over the said other end portions of said contacts. The other section of said plate has inclined planes formed on the inner surfaces thereof. A flat strip of material, which also has inclined planes on one surface thereof, fits in-between said second section of said plate and said housing, with the inclined plane surfaces mated to each other. By moving the flat strip in a first direction the said plate is pivoted about its flexible hinge so that said first section thereof forces the said other end portions of said contacts down into said U-shaped slot and against the edge of a circuit board inserted therein.

United States Patent Pritulsky (211 App]. No.: 442,955

[52] US. Cl. 339/75 MP; 339/176 MP [51} Int. Cl ..H()lr13/62 [58] Fieldof Search 339/17 R 17 L, 17 LM, 339/74 R, 75 R, 75 M. 75 MP. 176 R. 176M, 176 MP [56] References Cited UNITED STATES PATENTS 3.475.717 10/1969Lane 339/75 MP $555,488 1/1971 Mclver et a1 339/75 MP 3.596.230 7/1971Ecker 339/176 MP 3,665,370 5/1972 Hartmann.. 339/75 MP 3.818.419 6/1974Crane t v 339/74 R 3820.054 6/1974 Clewes et a1. 339/75 M [57] ABSTRACTA thin. board-to-board zero force insertion and with- 1 Aug. 5, 1975drawal connector having a housing containing a plurality of contactswith a first end portion of the contacts secured therein. A pair ofparallel rows of rib-like elements extend along the length of thehousing and define a Ushaped slot into which the edge of a circuit boardcan be inserted. The ribs form grooves therebetween which areperpendicular to the rows of ribs. The other end portion of each of saidcontacts extends downwardly into a groove towards the inner sides ofsaid rib-like elements defining a side of said U-shaped slot, and thenfurther extends upwardly towards the outer side of said riblikeelements. A plate is positioned along the length of said housing andsecured thereto by a flexible hinge which divides the platelongitudinally along its length into two sections. A first of thesesections extends over the said other end portions of said contacts. Theother section of said plate has inclined planes formed on the innersurfaces thereof. A flat strip of material, which also has inclinedplanes on one surface thereof, fits iii-between said second section ofsaid plate and said housing, with the inclined plane surfaces mated toeach other. By moving the fiat strip in a first direction the said plateis pivoted about its flexible hinge so that said first section thereofforces the said other end portions of said contacts down into saidU-shaped slot and against the edge of a circuit board inserted therein.

13 Claims, 3 Drawing Figures SHEET PATENTEB AUG 51975 ZERO INSERTIONFORCE CONNECTOR BACKGROUND OF THE INVENTION This invention relatesgenerally to connectors which connect one circuit board to anothercircuit board and more particularly to board-to-board connectors whichhave substantially zero insertion and withdrawal forces and which alsohave relatively small width dimensions, thereby allowing close spacingof a plurality of parallel daughter boards which are connected to acommon, perpendicularly positioned mother board.

The general concept of positioning several parallel daughter boards to acommon perpendicular mother board is well known in the art. One of theprimary problems involved in connecting one circuit board to anothercircuit board through a connector is the insertion and withdrawal forcesrequired for such connec tions and disconnections. In cases where thedaughter board has a large number of edge contacts, the cumulativeinsertion or withdrawal force can become quite large. totalling manytenths of pounds.

Since such high insertion or withdrawal forces pres ent obviousproblems, such as strain on the mother board and also possible damage toeach of the individual contacts of the daughter board, much effort hasbeen expended in developing what is known as zero force insertion andwithdrawal connectors. Most of these zero force insertion and withdrawalconnectors have some type of cam or lever arrangement which, in oneposition, causes the contacts within the connector to spread apart, orat least retreat from the mating contacts on the edge of the board beinginserted therein. After the circuit board is inserted, the lever or camis manually operated to cause the contacts within the connector to beforced down upon the mating contacts on the edge of the inserted printedcircuit board.

Such mechanisms are usually quite complex and fairly large so thatparallel positioned daughter boards must be spaced relatively far apartupon the common perpendicular mother board.

In modern electronic circuit packaging it is highly de sirable to spaceparallel daughter boards as close together as possible upon a commonmother board in order to provide a smaller overall package.

BRIEF STATEMENT OF THE INVENTION It is a primary object of the inventionto provide a board-to-board zero force insertion and withdrawalconnector having a relatively thin width, thereby permitting closespacing of parallel positioned daughter boards upon a common,perpendicular mother board.

A second purpose of the invention is to provide a zero insertion andwithdrawal board-to-board connector in which the zero force insertionand withdrawal enabling means requires a minimum of operating space,thereby allowing relatively close spacing of parallel daughter boards ona common mother board.

It is a third object of the invention to provide a relatively zero forceinsertion and withdrawal board-toboard connector which does not utilizecams or levers, but rather utilizes a series of mated inclined planeswhich are movable with respect to each other and which result in athinner connector, thereby allowing closer spacing of parallel daughterboards to a common perpendicular mother board than has heretofore beenpossible.

A fourth purpose of the invention is the improvement of zero forceinsertion and withdrawal circuit board connectors generally.

In accordance with the invention the board-to-board connector comprisesan electrically insulative housing having a plurality of contactssecurely retained therein. The housing consists of a first elongatedmain portion having a pair of parallel ledges extending along the lengththereof, which ledges define a U-shaped slot for receiving the edge of acircuit board insertable thereinv At least one of these two ledgescomprises a plurality of parallel ribs which form grooves therebetween.which grooves are perpendicular to the ledges.

Each of the contacts has one end portion thereof secured in the mainportion of the housing, and the other end portion thereof extendingfreely into one of said grooves and configured to have a section thereofextending towards the inner sides of the ribs which define one side ofsaid U-shaped slot and then extending away from said slot and towardsthe outer sides of the ribs. An elongated plate is positioned along thelength of said housing and is secured to the side of the housing by ahinge-like means which extends along the plate between the housing andthe plate and divides said plate longitudinally into first and secondsections, with the first section extending over the said other ends ofthe contacts and the second section having its inner surface formed intoat least one inclined plane which extends longitudinally along saidplate.

An actuator means, which is essentially a flat strip of plastic with amajor surface formed into at least one inclined plane configured to matewith the inclined plane surface of said plate, is inserted in betweenthe main portion of said housing and the second section of said plate.When said flat strip is moved longitudinally in a first direction itwill cause said mated inclined plane surfaces to move with respect toeach other, thereby pivoting the said plate about the hinge-like meansto cause said first section thereof to press down upon the said otherend portions of the contacts, thereby actuating said other end portionsof the contacts down into said slot and against mating contacts on theedge of the circuit board inserted therein.

When the flat strip is moved longitudinally in the opposite direction,the said second section of said plate is pivoted away from said otherend portions of said contacts to release the pressure between said otherend portions of said contacts and the circuit board inserted in the slotto permit removal or insertion of said circuit board with substantiallyzero force.

BRIEF DESCRIPTION OF THE DRAWINGS The above-mentioned and other objectsand features of the invention will be more fully understood from thefollowing detailed description thereof when read in conjunction with thedrawings in which:

FIG. 1 is a perspective, cross-sectional view of the connector of theinvention showing in detail how a daughter board is connected to amother board thereby;

FIG. 2 is a plan view of a cross-section of the connector, and alsoshows how a daughter board is connected to a mother board; and

FIG. 3 is a perspective view of a combination structure showing how asingle daughter board can be connected to two mother boards through theuse of two of the connectors of the present invention.

DETAILED DESCRIPTION OF THE INVENTION Referring now to FIG. 1, adaughter board 10 is shown connected to a mother board 11 through theconnector of the invention, denoted ganerally by reference character 12.

Basically, connector 12 consists of a housing comprised of four mainportions and a plurality of contacts retained therein. The first housingportion, designated herein as the main portion of the housing. isidentified by reference character 13, and includes that portion of theconnector housing in which the retained contacts. such as contacts 20and 2], are secured.

It is to be noted that only a portion, i.e., the center portion, of thecontacts are secured in main portion 13 of the housing. For purposes ofdescription herein, this center portion of the contacts 20 and 21 isdefined in the specification and in the claims as the first end portionof the contacts.

Actually, however, the two contacts 20 and 21 extend through and out theend of the main portion 13 of the connector housing to form terminalposts desig nated generally by reference characters 22 and 23 and whichfit through apertures 40 and 41 provided there fore in the mother boardII.

The second portion of the connector 12 consists of two rows of ribs,designated generally as 14 and IS in FIG. I, and which extend along theentire length of housing 12 and define a U-shaped groove thereinbe tweeninto which the daughter board 10 is inserted. as shown in FIG. I.

The third portion of the connector housing 12 consists of the two plates25 and 26 which are secured to the main portion of the housing by meansof flexible hinge-like elements 27 and 28, respectively. These flexiblehinge-like elements 27 and 28 are in fact hinges about which the plates25 and 26 can pivot.

The last of the four main portions of connector housing 12 consists ofthe two flat strips 30 and 3i, of which only the ends can be seen inFIG. I. The flat strips 30 and 3] are shown in more detail in FIG. 3 andcan be seen to have one surface which is essentially a series ofiterative inclined planes which mate with mirrored iterative inclinedplanes in the associated plate 25.

While the mating of the inclined planes in plate 26 and flat strip 3]cannot be seen in FIG. 3, a correspond' ing mating of inclined planes ina similar connector 50, also shown in FIG. 3, can be seen. Morespecifically, the inclined planes S2, 53, 54 and 55 of flat strip 40 andthe mating and mirrored inclined planes 56, 57, 58, 59 and 60 of plate61, which corresponds to plate 26 in connector 12, can be seen in FIG.3.

Returning again to FIG. 1, the contacts, such as the pair of contacts 20and 2], can be seen. The center portion thereof of the contacts 20 and2], also called the first end portion, is securely retained within themain portion 13 of connector 12, as has already been dis' cussed. Theother end portion, that is the free end portion of the contacts 20 and21 to the left of the first end portion in FIG. I, extends into thegrooves between the ribs of the row of ribs 14. Such grooves aredesignated, for example, by reference characters l7, l8 and 19 inFIG. 1. The internal configuration of one of these grooves is shown bestby the groove represented by reference character 19. It can be seen thatthe free or other end portion of the contact 21, i.e., the left handportion of the contact 21, extends into the groove 19 and then has abent-down or convex section designated generally by reference character36, which extends nearly to the inner sides of the row of ribs 15, whichinner sides define one edge of the main slot into which the edge of thedaughter board can be inserted.

The said free or other end portion of contact 21 then extends furthertowards the outside tip of the row of ribs and upwardly towards theplate 26 and, in fact, extends beyond the outer sides of the row of ribsand comes very close to or can actually make contact with the innersurface of the overhanging portion of the plate 26, as shown in FIG. Iat point 42.

As mentioned above, the plate and also the plate 26 pivot about theflexible hinges 27 and 28, respec tively. For purposes of discussion,however, only plate 25 and its pivoting action around hinge 27 will bediscussed herein since its action is the same as the pivoting action ofplate 26 around its hinge 28.

It is apparent that if the plate 25 is pivoted in a clock wise directionaround hinge 27, the left hand section of plate 25 will bear up upon theends of the contacts, such as contact 20, and will force the convexportion 16 thereof into firm contact with the edge of the daughtercircuit board I0, which has previously been inserted into slot 82 (seeFIG. 2) of connector 12 with zero in sertion force.

The means by which the plate 25 is caused to pivot around hinge 27 isflat strip which has inclined plane portions thereon similar to theinclined planes and 39 which are shown on strip 31 of FIG. 3.

For purposes of clarity of description of the foregoing consider theflat strip 40 and the plate 61 shown in FIG. 3, which correspondprecisely to the flat strip 30 and the plate 25 of FIG. I, but whichshow more clearly the relationship therebetween.

The flat strip 40 is first inserted in a lateral or transverse manner inthe direction of the arrow 80 in the gap between plate 61 and the sideof the main portion of the connector 50. The strip 40 is initiallyinserted in such a manner that the inclined planes 5] of the strip 40and the inclined plates 56 60 mate completely with each other over theirfull surfaces. Thus, for example, the inclined plane or ramp 5] matessub stantially over its entire surface with the mating ramp or inclinedsurface 56 of plate 61.

If now the flat strip 40 is moved to the left in FIG. 3, in thedirection of arrow 75, it is apparent that the corresponding inclinedplane will ride up each other, thereby pushing the left hand section 86of plate 61 upwardly and the right hand section 87 downwardly upon thecontacts which lie within the connector 50, but which are not shown.

The lower flat strip 41 of connector 50 is shown as being in itsactuated position so that plate 62 has been pivoted about its flexiblehinge (not shown) and the lower band of contacts (also not shown) havebeen brought to bear firmly against the underside of the daughter board63.

Once the flat strips are inserted in the connector, such as connector50, and are either in their nonactuated condition or their actuatedcondition, the connector 50 can be attached to the mother board by meansof the bank of post-like terminals 65, as shown in FIG. 3. Subsequently,the daughter board 63 can be either inserted and withdrawn withsubstantially zero force simply by manual operation of the two flatstrips 40 and 41 into their actuated and non-actuated positions.

Reference is made to FIG. 2 which shows even more clearly theinteraction between the flat strips 30 and 31, the plates 25 and 26 andthe contacts 20 and 21. More specifically, in FIG. 2 the plates 30 and31 are shown in their actuated positions so that the portions 46 and 47of the plates 25 and 26 are pivoted towards and into the end portions 48and 49 of contacts 20 and 21 about flexible hinges 27 and 28respectively.

More specifically consider the plate 25 individually. The flat strip 31is shown in its actuated position, thereby pushing the section 46 ofplate 25 against the end portion 48 of contact 20. The contact portion16 of contact 20 moves freely within the grooved area between adjacentribs, of which rib 14 is shown, and is forced into the edge of thedaughter board 10. Presum ably, a contact will be present on the edge ofdaughter board at the point into which the section 16 of contact isforced, thereby making good electrical contact with the daughter board10. Also, a mechanical gripping of the mother board within the connector12 is effected by means of contact 20 being forced against said daughterboard 10.

If it is desired to remove the daughter board 10 from connector 12 it isonly necessary that the flat actuator strips 30 and 31 be moved to theirnon-actuated positions, thereby pivoting the portions 46 and 47 ofplates and 26 outwardly and away from the ends 48 and 49 of the contacts20 and 21. The convex portions 16 and 36 of contacts 20 and 21 therebymove away from daughter board 10 and release the pressure therefrom toallow removal of said daughter board 10 from the slot 82 withsubstantially zero force.

Referring again to FIG. 3 there is shown a structure whereby a singledaughter board 63 can be connected to two mother boards (not shown)through connectors 12 and 50 respectively. One of the mother boards canbe connected to the array of post-like terminals 65 on connector 50, andthe other mother board can be connected to the post-like terminals, suchas post terminal 68 of connector 12.

It is further to be understood that the plurality of daughter boards,such as daughter board 63 can be stacked, one upon the other in parallelmanner, with each daughter board being connected to one or both of thetwo mother boards. Thus in FIG. 1, connectors 12, 88 and 89 can bepositioned side-by-side on each mother board so that the spacing betweenthe daughter board is equal substantially to the thickness of theconnectors l2 and 88. In one practical form of the invention whichactually has been constructed, the connectors l2 and 88 are eachslightly less than one-half inch thick so that daughter boards 10 can bestacked in parallel manner approximately one-half inch apart.

Referring now specifically to some details of the flat strip 31 of FlG.3, it can be seen that such flat strip 31 has two end plates 70 and 71which function as a means for moving the flat strip back and forth inthe connec tor 12 and also function as stops so that the flat strip 31can move in either direction only to the point to where the end plates70 and 71 abut against the end of the connector 12.

It is not necessary that the portion 69 of the flat strip 31 be aninclined plane since it simply represents that portion of the length ofthe flat strip 31 which extends out of the connector 12 when the flatstrip 31 is in its nonactuated condition. More specifically, the section69 permits the flap strip 31 to be moved back and forth and is not apart of the inclined plane surfaces which pivots the plane 26 about itsflexible hinge 28.

The connector 12 is provided with slots in the ends thereof, such asslot 72 so that the flat strip 31 can be inserted in between the plate26 and the main portion of the housing before the connector is securedto the mother board by means of post-like terminals 68.

It is to be understood that the form of the invention shown anddescribed herein is but a preferred embodiment thereof, and that variouschanges, such as for example, the number of inclined surfaces on theflat strips and the pivoting plates, or the particular configuration ofthe contacts, can be made without departing from the spirit or scope ofthe invention.

What is claimed is:

1. A circuit board connector comprising a housing and a plurality ofcontacts retained therein;

said housing comprising a first elongated main portion having a pair ofparallel ledges extending along the length thereof with their innersurfaces defining a slot to receive the edge of a first circuit boardtherein;

at least one of said ledges comprising a plurality of ribs formingparallel grooves therebetween which are perpendicular to said ledges;

each of said plurality of contacts having a first end portion thereofsecured in said main portion of said housing and the other end portionthereof extending into one of said grooves and configured to have asection thereof extending towards the inner surface of said ledge whichdefines one side of said slot and with the end of said other end portionextending away from said slot and towards the outer surface of saidledge;

said housing further comprising an elongated plate extending along thelength of said housing and se cured to said housing by a flexible,hinge-like element which extends along at least a portion of the lengthof said housing and is parallel to the center line of said elongatedplate;

a first section of said plate on one side of said hingelike elementextending over the said other ends of said contacts;

a second section of said plate on the other side of said hinge-likeelement having its inner surface comprising a series of inclined planesextending longitudinally along said plate; and

an actuator means comprising an elongated flat strip with one of its twomajor surfaces formed into a series of inclined planes configured tomate with the inclined planes on said plate;

said flat strip insertable in between said main portion of said housingand said second section of said plate, and movable longitudinally in afirst direction to cause said mated inclined planes to move with respectto each other, thereby pivoting the said plate about said hinge-likemeans to cause said first section of said plate to press down upon theends of said other end portions of said contacts and thereby actuatesaid sections of said contacts down into said slot and against matingcontacts provided on the edge of said circuit board inserted in saidslot.

2. A circuit board connector in accordance with claim 1 in which saidflat strip is movable in a second direction to release the pressure ofsaid first section of said plate upon said ends of said other endportions of said contacts to enable withdrawal of said first circuitboard from said slot with substantially zero force.

3. A circuit board connector in accordance with claim 1 in which thesaid other end portion of each of said contacts has a section thereofwhich is convex with respect to the inner surface of said ribs on saidledge which defines said slot and which extends when not ac tuated,inwardly towards the inner surface of said ledge ribs which define saidslot, but not into said slot to an extent which will impede theinsertion of the edge of said first circuit board.

4. A circuit board connector in accordance with claim 1 in which saidfirst end portions of said contacts extend through said main portion ofsaid housing to form terminals which fit into mating terminals containedin a second circuit board, thereby forming a first circuit board tosecond circuit board connection.

5. A zero entry force circuit board connector com prising a housing anda plurality of contacts retained therein;

said housing comprising a first elongated main portion having at leastone row of parallel ribs extending along the length thereof and a ledgeextending along the length thereof; said row of parallel ribs and saidledge defining an elongated slot therebetween to receive the edge of acircuit board therein;

said row of ribs forming grooves therebetween which are substantiallynormal to the longitudinal direc tion of said elongated slot; each ofsaid plurality of contacts having one end por tion thereof secured insaid main portion of said housing and the other end portion thereofextend ing into one of said grooves and configured to have a sectionthereof extend towards the inner sides of said ribs which define oneside of said slot, and with the end of said other end portion extendingaway from said slot and towards the outer sides of said ribs; anelongated plate extending along the length of said housing and securednear its midpoint to the out side surface of said housing by ahinge-like means extending along a line which divides said elongatedplate longitudinally into first and second sections;

said first section extending over the said other ends of said contacts;

said second section having its inner surface comprising at least oneinclined plane surface extending longitudinally along said elongatedplate; and

an actuator means comprising an elongated flat strip with a majorsurface formed into at least one inclined plane surface configured tomate with the inclined plane surface of said plate;

said flat strip being insertable in between said main portion of saidhousing and said second section of said plate, and movablelongitudinally in a first direction to cause said mated inclined planesurfaces to move with respect to each other and thereby pivot the saidplate about said hinge-like means to cause said first section thereof topress down upon said ends of said other end portions of said contactsand thereby actuate said other end portions of said contacts down intosaid slot and against mating contacts on the edge of said circuit boardinserted therein.

6. A circuit board connector in accordance with claim 5 in which saidflat strip is movable in a second direction to release the pressure ofsaid first section of said plate upon said ends of said other endportions of said contacts to enable withdrawal of said circuit boardfrom said slot with substantially Zero force.

7. A circuit board connector in accordance with claim 5 in which thesaid other end portion of each of said contacts has a section thereofwhich is convex with respect to the inner surface of said ribs on saidledge which define said slot and which extends, when not actuated.inwardly towards the inner sides of said ribs which define said slot,but not into said slot to any ex tent which would impede the insertionof the edge of said circuit board therein.

8. A circuit board connector in accordance with claim 5 in which saidfirst end portions of said contacts extend through said main portions ofsaid housings to form terminals which fit into mating terminalscontained in a second circuit board. thereby forming a circuit board tocircuit board connection.

9. A circuit board connector comprising a housing and a plurality ofcontacts retained therein;

said housing comprising a first elongated main p0rtion having a pair ofrows of parallel ribs extending along the length thereof and defining anelongated slot therebetween to receive the edge of a circuit boardtherein;

said ribs of each row forming grooves therebetween which areperpendicular to the longitudinal direction of said elongated slot;

each of said plurality of contacts having one end portion thereofsecured in said main portion of said housing and the other end portionthereof config ured to extend into one of said grooves towards the sidesof said ribs which define one side of said slot, and then to extend awayfrom said slot and towards the outer sides of said ribs;

an elongated plate extending along the length of said housing andsecured to the side of said housing by a hinge-like means extendingalong a line which divides said elongated plate longitudinally intofirst and second sections;

said first section extending over the said other end portions of saidcontacts;

said second section having its inner surface comprising at least oneinclined plane extending longitudinally along said plate; and

an actuator means comprising an elongated flat strip with a majorsurface formed into at least one in clined plane configured to mate withthe inclined plane surface of said plate;

said flat strip being insertable in between said main portion of saidhousing and said second section of said plate, and movablelongitudinally in a first direction to cause said mated inclined planesurfaces to move with respect to each other and thereby pivot the saidplate about said hinge-like means and cause said first section to pressdown upon said other end portions of said contacts and thereby actuatesaid contacts down into said slot and against mating contacts on theedge of said circuit board inserted therein.

10. A circuit board connector in accordance with claim 9 in which saidflat strip is movable in a second direction to release the pressure ofsaid first section of said plate upon said other end portions of saidcontacts to enable withdrawal of said circuit board from said slot withsubstantially zero force.

11. A circuit board connector in accordance with claim 9 in which thesaid other end portion of each of said contacts has a section thereofwhich is convex with respect to the inner surface of said ribs whichdefine said slots and which extends when not actuated, inwardly towardsthe inner sides of said ribs which define said slot, but not into saidslot to any extent which impedes the insertion of the edge of saidcircuit board.

12. A circuit board connector in accordance with claim 9 in which saidfirst end portions of said contacts extend through said main portions ofsaid housings to form terminals which fit into mating terminalscontained in a second circuit board, thereby forming a circuit board tocircuit board connection.

13. A zero entry force circuit board connector comprising a housing anda plurality of contacts retained therein;

said housing comprising a first elongated main portion having at leastone row of parallel ribs extending along the length thereof and a ledgeextending along the length thereof; said row of parallel ribs and saidledge defining an elongated slot therebetween to receive the edge of acircuit board therein;

said ribs forming grooves therebetween which are substantially normal tothe longitudinal direction of said elongated slot;

each of said plurality of contacts having one end por tion thereofsecured in said main portion of said housing and the other end portionthereof extend ing into one of said grooves towards the sides of saidribs which define one side of said slot and then extending away fromsaid slot and towards the outer sides of said ribs;

an elongated plate extending along the length of said housing andsecured to the side of said housing by a hinge-like means extendingalong a line which divides said elongated plate longitudinally intofirst and second sections;

said first section extending over the said other end portions of saidcontacts;

said second section having its inner surface comprising at least oneinclined plane extending longitudinally along said plate; and

an actuator means comprising an elongated flat strip with a majorsurface formed into at least one inclined plane configured to mate withthe inclined plane surface of said plate;

said flat strip being insertable in between said main portion of saidhousing and said second section of said plate, and movablelongitudinally in a first di rection to cause said mated inclined planesurfaces to move with respect to each other and thereby pivot the saidplate about said hinge like means to cause said first section to pressdown upon said other end portions of said contacts and thereby actuatesaid other end portions of said contacts down into said slot and againstmating contacts on the edge of said circuit board inserted therein

1. A circuit board connector comprising a hOusing and a plurality ofcontacts retained therein; said housing comprising a first elongatedmain portion having a pair of parallel ledges extending along the lengththereof with their inner surfaces defining a slot to receive the edge ofa first circuit board therein; at least one of said ledges comprising aplurality of ribs forming parallel grooves therebetween which areperpendicular to said ledges; each of said plurality of contacts havinga first end portion thereof secured in said main portion of said housingand the other end portion thereof extending into one of said grooves andconfigured to have a section thereof extending towards the inner surfaceof said ledge which defines one side of said slot and with the end ofsaid other end portion extending away from said slot and towards theouter surface of said ledge; said housing further comprising anelongated plate extending along the length of said housing and securedto said housing by a flexible, hinge-like element which extends along atleast a portion of the length of said housing and is parallel to thecenter line of said elongated plate; a first section of said plate onone side of said hinge-like element extending over the said other endsof said contacts; a second section of said plate on the other side ofsaid hingelike element having its inner surface comprising a series ofinclined planes extending longitudinally along said plate; and anactuator means comprising an elongated flat strip with one of its twomajor surfaces formed into a series of inclined planes configured tomate with the inclined planes on said plate; said flat strip insertablein between said main portion of said housing and said second section ofsaid plate, and movable longitudinally in a first direction to causesaid mated inclined planes to move with respect to each other, therebypivoting the said plate about said hinge-like means to cause said firstsection of said plate to press down upon the ends of said other endportions of said contacts and thereby actuate said sections of saidcontacts down into said slot and against mating contacts provided on theedge of said circuit board inserted in said slot.
 2. A circuit boardconnector in accordance with claim 1 in which said flat strip is movablein a second direction to release the pressure of said first section ofsaid plate upon said ends of said other end portions of said contacts toenable withdrawal of said first circuit board from said slot withsubstantially zero force.
 3. A circuit board connector in accordancewith claim 1 in which the said other end portion of each of saidcontacts has a section thereof which is convex with respect to the innersurface of said ribs on said ledge which defines said slot and whichextends, when not actuated, inwardly towards the inner surface of saidledge ribs which define said slot, but not into said slot to an extentwhich will impede the insertion of the edge of said first circuit board.4. A circuit board connector in accordance with claim 1 in which saidfirst end portions of said contacts extend through said main portion ofsaid housing to form terminals which fit into mating terminals containedin a second circuit board, thereby forming a first circuit board tosecond circuit board connection.
 5. A zero entry force circuit boardconnector comprising a housing and a plurality of contacts retainedtherein; said housing comprising a first elongated main portion havingat least one row of parallel ribs extending along the length thereof anda ledge extending along the length thereof; said row of parallel ribsand said ledge defining an elongated slot therebetween to receive theedge of a circuit board therein; said row of ribs forming groovestherebetween which are substantially normal to the longitudinaldirection of said elongated slot; each of said plurality of contactshaving one end portion thereof secured in said main portion of saidhousing and the other end portiOn thereof extending into one of saidgrooves and configured to have a section thereof extend towards theinner sides of said ribs which define one side of said slot, and withthe end of said other end portion extending away from said slot andtowards the outer sides of said ribs; an elongated plate extending alongthe length of said housing and secured near its midpoint to the outsidesurface of said housing by a hinge-like means extending along a linewhich divides said elongated plate longitudinally into first and secondsections; said first section extending over the said other ends of saidcontacts; said second section having its inner surface comprising atleast one inclined plane surface extending longitudinally along saidelongated plate; and an actuator means comprising an elongated flatstrip with a major surface formed into at least one inclined planesurface configured to mate with the inclined plane surface of saidplate; said flat strip being insertable in between said main portion ofsaid housing and said second section of said plate, and movablelongitudinally in a first direction to cause said mated inclined planesurfaces to move with respect to each other and thereby pivot the saidplate about said hinge-like means to cause said first section thereof topress down upon said ends of said other end portions of said contactsand thereby actuate said other end portions of said contacts down intosaid slot and against mating contacts on the edge of said circuit boardinserted therein.
 6. A circuit board connector in accordance with claim5 in which said flat strip is movable in a second direction to releasethe pressure of said first section of said plate upon said ends of saidother end portions of said contacts to enable withdrawal of said circuitboard from said slot with substantially zero force.
 7. A circuit boardconnector in accordance with claim 5 in which the said other end portionof each of said contacts has a section thereof which is convex withrespect to the inner surface of said ribs on said ledge which definesaid slot and which extends, when not actuated, inwardly towards theinner sides of said ribs which define said slot, but not into said slotto any extent which would impede the insertion of the edge of saidcircuit board therein.
 8. A circuit board connector in accordance withclaim 5 in which said first end portions of said contacts extend throughsaid main portions of said housings to form terminals which fit intomating terminals contained in a second circuit board, thereby forming acircuit board to circuit board connection.
 9. A circuit board connectorcomprising a housing and a plurality of contacts retained therein; saidhousing comprising a first elongated main portion having a pair of rowsof parallel ribs extending along the length thereof and defining anelongated slot therebetween to receive the edge of a circuit boardtherein; said ribs of each row forming grooves therebetween which areperpendicular to the longitudinal direction of said elongated slot; eachof said plurality of contacts having one end portion thereof secured insaid main portion of said housing and the other end portion thereofconfigured to extend into one of said grooves towards the sides of saidribs which define one side of said slot, and then to extend away fromsaid slot and towards the outer sides of said ribs; an elongated plateextending along the length of said housing and secured to the side ofsaid housing by a hinge-like means extending along a line which dividessaid elongated plate longitudinally into first and second sections; saidfirst section extending over the said other end portions of saidcontacts; said second section having its inner surface comprising atleast one inclined plane extending longitudinally along said plate; andan actuator means comprising an elongated flat strip with a majorsurface formed into at least one inclined plane configured to mate withthe inclinEd plane surface of said plate; said flat strip beinginsertable in between said main portion of said housing and said secondsection of said plate, and movable longitudinally in a first directionto cause said mated inclined plane surfaces to move with respect to eachother and thereby pivot the said plate about said hinge-like means andcause said first section to press down upon said other end portions ofsaid contacts and thereby actuate said contacts down into said slot andagainst mating contacts on the edge of said circuit board insertedtherein.
 10. A circuit board connector in accordance with claim 9 inwhich said flat strip is movable in a second direction to release thepressure of said first section of said plate upon said other endportions of said contacts to enable withdrawal of said circuit boardfrom said slot with substantially zero force.
 11. A circuit boardconnector in accordance with claim 9 in which the said other end portionof each of said contacts has a section thereof which is convex withrespect to the inner surface of said ribs which define said slots andwhich extends, when not actuated, inwardly towards the inner sides ofsaid ribs which define said slot, but not into said slot to any extentwhich impedes the insertion of the edge of said circuit board.
 12. Acircuit board connector in accordance with claim 9 in which said firstend portions of said contacts extend through said main portions of saidhousings to form terminals which fit into mating terminals contained ina second circuit board, thereby forming a circuit board to circuit boardconnection.
 13. A zero entry force circuit board connector comprising ahousing and a plurality of contacts retained therein; said housingcomprising a first elongated main portion having at least one row ofparallel ribs extending along the length thereof and a ledge extendingalong the length thereof; said row of parallel ribs and said ledgedefining an elongated slot therebetween to receive the edge of a circuitboard therein; said ribs forming grooves therebetween which aresubstantially normal to the longitudinal direction of said elongatedslot; each of said plurality of contacts having one end portion thereofsecured in said main portion of said housing and the other end portionthereof extending into one of said grooves towards the sides of saidribs which define one side of said slot and then extending away fromsaid slot and towards the outer sides of said ribs; an elongated plateextending along the length of said housing and secured to the side ofsaid housing by a hinge-like means extending along a line which dividessaid elongated plate longitudinally into first and second sections; saidfirst section extending over the said other end portions of saidcontacts; said second section having its inner surface comprising atleast one inclined plane extending longitudinally along said plate; andan actuator means comprising an elongated flat strip with a majorsurface formed into at least one inclined plane configured to mate withthe inclined plane surface of said plate; said flat strip beinginsertable in between said main portion of said housing and said secondsection of said plate, and movable longitudinally in a first directionto cause said mated inclined plane surfaces to move with respect to eachother and thereby pivot the said plate about said hinge-like means tocause said first section to press down upon said other end portions ofsaid contacts and thereby actuate said other end portions of saidcontacts down into said slot and against mating contacts on the edge ofsaid circuit board inserted therein.